The word(s) "believer" appears 309 time(s) in 259 verse(s) in Quran in Abdullah Yusuf Ali translation.

(61) O Prophet! sufficient unto thee is Allah,- (unto thee) and unto those who follow thee among the believers.

(62) O Prophet! rouse the believers to the fight. If there are twenty amongst you, patient and persevering, they will vanquish two hundred: if a hundred, they will vanquish a thousand of the Unbelievers: for these are a people without understanding.

(63) The Unbelievers are protectors, one of another: Unless ye do this, (protect each other), there would be tumult and oppression on earth, and great mischief.

(64) Those who believe, and adopt exile, and fight for the Faith, in the cause of Allah as well as those who give (them) asylum and aid,- these are (all) in very truth the believers: for them is the forgiveness of sins and a provision most generous.

(65) In a believer they respect not the ties either of kinship or of covenant! It is they who have transgressed all bounds.

(66) Fight them, and Allah will punish them by your hands, cover them with shame, help you (to victory) over them, heal the breasts of believers,

(67) Or think ye that ye shall be abandoned, as though Allah did not know those among you who strive with might and main, and take none for friends and protectors except Allah, His Messenger, and the (community of) believers? But Allah is well-acquainted with (all) that ye do.

(68) But Allah did pour His calm on the Messenger and on the believers, and sent down forces which ye saw not: He punished the Unbelievers; thus doth He reward those without Faith.

(69) The Jews call 'Uzair a son of Allah, and the Christians call Christ the son of Allah. That is a saying from their mouth; (in this) they but imitate what the unbelievers of old used to say. Allah's curse be on them: how they are deluded away from the Truth!

(70) Fain would they extinguish Allah's light with their mouths, but Allah will not allow but that His light should be perfected, even though the Unbelievers may detest (it).